18159999 has 16 divisors (see below), whose sum is σ = 28447104. Its totient is φ = 10159200.

The previous prime is 18159989. The next prime is 18160013. The reversal of 18159999 is 99995181.

It is a de Polignac number, because none of the positive numbers 2^k-18159999 is a prime.

18159999 is a modest number, since divided by 9999 gives 1815 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18159959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20737 + ... + 21594.

It is an arithmetic number, because the mean of its divisors is an integer number (1777944).

Almost surely, 2^18159999 is an apocalyptic number.

18159999 is a deficient number, since it is larger than the sum of its proper divisors (10287105).

18159999 is a wasteful number, since it uses less digits than its factorization.

18159999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42358.

The product of its digits is 262440, while the sum is 51.

The square root of 18159999 is about 4261.4550332017. The cubic root of 18159999 is about 262.8483610718.

The spelling of 18159999 in words is "eighteen million, one hundred fifty-nine thousand, nine hundred ninety-nine".